First, obtain the lease on two blocks; a normal block and an unbuildable one, such as a railroad or utility. Click on the normal block and click on the "Build" icon. The game will ask you if you want to activate building rights. Now, click on the railroad or utility and it will ask you if you want to activate building rights for it. Say yes, and you can build on the normally unbuildable block. If you want to build more, you have to click on the normal block again so it asks you if you want to activate building rights. Then page over to the block you just built on. This is great in the "Race for Mayor" and "Last Man Standing" scenarios because you can landscape an entire railroad or utility without losing space to build your business empire.